Fastener Driver Tool

This application claims the benefit of priority of U.S. provisional application Ser. No. 63/649,780, filed on May 20, 2024 the disclosure of which is herein incorporated by reference in its entirety.

This disclosure relates to the field of power tools and particularly to devices and tools used to drive fasteners into workpieces.

Fasteners such as nails and staples are commonly used in projects ranging from crafts to building construction. While manually driving such fasteners into a workpiece is effective, a user may quickly become fatigued when involved in projects requiring a large number of fasteners and/or physically large fasteners to be driven into a workpiece. Moreover, proper driving of larger fasteners into a workpiece frequently requires more than a single impact from a manual tool.

In response to the shortcomings of manual driving tools, power-assisted devices for driving fasteners into workpieces have been developed. Contractors and homeowners commonly use such devices for driving fasteners ranging from brad nails used in small projects, to common nails which are used in framing and other construction projects, to staples which are used in large and small projects. Compressed air has been traditionally used to provide power for the power-assisted (pneumatic) devices. Specifically, a source of compressed air is used to actuate a cylinder which impacts a nail into the workpiece. Such systems, however, require an air compressor, increasing the cost of the system and limiting the portability of the system. In response, fuel cells were developed for use as a source of power for power-assisted devices. The fuel cell is generally provided in the form of a cylinder which is removably attached to the device. Systems with fuel cells rely on the rapid expansion of a gas to the cylinder and thus impact a fastener into a workpiece. These systems are relatively complicated as both electrical systems and fuel systems are required to produce the expansion of gases.

Another source of power that has been used in power assisted devices is electrical power. Traditionally, electrical devices have been mostly limited to use in impacting smaller fasteners such as staples, tacks, and brad nails. In these devices, a solenoid driven by electrical power from an external source is used to impact the fastener. The force that can be achieved using a solenoid, however, is limited by the physical structure of the solenoid. Various approaches have been used to address the limitations of electrical devices. In some systems, multiple impacts are used. This approach requires the tool to be maintained in position for a relatively long time to drive a fastener. Another approach is the use of a spring to store energy. In this approach, the spring is cocked (or activated) through an electric motor. Once sufficient energy is stored within the spring, the energy is released from the spring into an anvil which then impacts the fastener into the substrate.

Other fastener drivers use a flywheel to store energy for use in impacting a fastener. The flywheel is used to launch a hammering anvil that impacts the nail or other fastener. A DC motor rotates the flywheel and once a predetermined flywheel speed is reached the flywheel is moved into engagement with a driving mechanism that impacts a fastener at the end of a fastener magazine. Details of a fastener driver using a flywheel mechanism are disclosed in U.S. Pat. Nos. 7,934,565 and 8,746,526, the disclosures of which are incorporated herein.

The fasteners, such as nails or staples, are held in a magazine or cartridge that is mounted to body of the fastener driver. The magazine provides a uniform guide track that allows the fasteners to enter the drive mechanism with a proper and consistent alignment. A consideration with nailer assemblies is the weight of the assembly. The housing and drive mechanism of the fastener driver can weigh 7-10 lbs. A magazine holding a sufficient number of fasteners to preclude excessive time refilling the driver or nailer assembly can result in a substantial weight of fasteners, on the order of 1-2 lbs. when the fasteners are relatively large and heavy. The overall weight can be tiresome for a handheld tool, especially when the tool is used to drive fasteners horizontally into a workpiece, such as when mounting a trim piece to a vertical wall. Moreover, and equally significantly, the orientation of the weight of the conventional fastener driver makes the tool cumbersome to align properly relative to the workpiece.

In the example tool T shown in, a center of gravity CG of the tool T is significantly offset from the fastener magazine M and the impact point I of the tool. Moreover, the hand grip G is significantly offset from the impact point I. The position of the hand grip G and the center of gravity CG relative to the impact point I produces a counter-clockwise moment as the user tries to maneuver the tool into proper alignment for driving the fastener into the workpiece. This moment is aggravated by the cantilevered loads due to the weight of the tool T as the user manipulates the tool at arm's length, as depicted in. This moment imposes a load on the user's wrist as the user works to resist the moment while maneuvering the tool T.

According to an exemplary embodiment of the disclosure, a fastener driver tool includes a housing, a drive mechanism, a battery pack, and a fastener magazine. The housing has a grip portion located between a power supply portion and a drive portion. The drive mechanism includes (i) a motor, (ii) a gearbox operably connected to the motor, and (iii) a striking mechanism operably connected to the gearbox. The battery pack is received by the power supply portion and is operably connected to the motor. The fastener magazine is configured to hold a plurality of fasteners. The fastener magazine is mounted on the housing and operably connected to the striking mechanism. The motor and the gearbox are located in the grip portion of the housing. The striking mechanism is located in the drive portion of the housing. The striking mechanism is configured to strike a corresponding fastener of the plurality of fasteners using rotation from the gearbox as rotated by the motor supplied with electrical energy from the battery pack. A center of gravity of the fastener driver tool is located within the grip portion.

According to another exemplary embodiment of the disclosure, a fastener driver tool includes a housing a drive mechanism, a power supply, and a fastener magazine. The housing has a grip portion located between a power supply portion and a drive portion. The drive mechanism includes (i) a motor, (ii) a gearbox operably connected to the motor, and (iii) a striking mechanism operably connected to the gearbox. The power supply is received by the power supply portion and is configured to supply the motor with electrical energy. The fastener magazine is configured to hold a plurality of fasteners. The fastener magazine is mounted on the housing and operably connected to the striking mechanism. The motor and the gearbox are located in the grip portion of the housing. The striking mechanism is located in the drive portion of the housing. The striking mechanism is configured to strike a corresponding fastener of the plurality of fasteners using rotation from the gearbox as rotated by the motor. A center of gravity of the fastener driver tool is located within the gearbox.

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the disclosure is thereby intended. It is further understood that this disclosure includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the disclosure as would normally occur to one skilled in the art to which this disclosure pertains.

Aspects of the disclosure are disclosed in the accompanying description. Alternate embodiments of the disclosure and their equivalents may be devised without parting from the spirit or scope of the disclosure. It should be noted that any discussion herein regarding “one embodiment,” “an embodiment,” “an exemplary embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, and that such particular feature, structure, or characteristic may not necessarily be included in every embodiment. In addition, references to the foregoing do not necessarily comprise a reference to the same embodiment. Finally, irrespective of whether it is explicitly described, one of ordinary skill in the art would readily appreciate that each of the particular features, structures, or characteristics of the given embodiments may be utilized in connection or combination with those of any other embodiment discussed herein.

For the purposes of the disclosure, the phrase “A and/or B” means (A), (B), or (A and B). For the purposes of the disclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).

The terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the disclosure, are synonymous.

According to the present disclosure, a fastener driver toolis provided that addresses the weight and balance problems of the prior art driver tools, such as the tool T shown in. As shown in, the toolincludes a housing, a battery pack, and a fastener magazine. A drive mechanism() of the toolis located within the housing. As described herein, a center of gravityof the toolis optimally located to balance the tooland to reduce the undesirable moments and cantilevered loads of the prior art tool T, thereby making the toolof the present disclosure more comfortable to operate. Each element of the toolis described below.

The housing, in one embodiment, is formed of a lightweight and durable material, such as a plastic or resin material. For example, the housingis formed of two mating halves and includes interior features (see) to support and orient the working components of the tool. The housingdefines a hand grip portion, a power supply portion, a drive portion, and a cartridge support portion. It can be appreciated fromthat the drive portionand the power supply portionare arranged to flank the grip portion, essentially forming an ergonomic saddle between the two portions,for a comfortable and stable grip by the user.

In one embodiment, the grip portionis barrel-shaped and ergonomically configured for a comfortable grip by the user. The hand grip portionis offset from the cartridge support portion, such that the housingdefines a finger openingsized to receive the fingers of the user when gripping the grip portion. The grip portionis located between the power supply portionand the drive portion. The finger openingis located between the grip portionand fastener magazine. The grip portiondefines a longitudinal grip axis, and the finger openingdefines a finger longitudinal axisthat is parallel to the longitudinal grip axis.

The fastener magazineis mounted on the cartridge support portionof the housing. The fastener magazineis configured to hold a plurality of fastenersone of which is shown in. The fastener magazinecontains any type of fastener, such as nails and staples, and is configured to be reloaded as needed. The fastener magazinefeeds the fastenersto an impact pointof the toolwhere the drive mechanismimpacts the fastenerto drive the fastenerinto a workpiece.

The power supply portioncontains and/or supports a power supply of the tool. As shown in, the exemplary power supply is the removable and rechargeable battery pack. The battery packis received by the power supply portionof the housing. The battery packprovides electrical energy. In another embodiment, the power supply an AC power supply (not shown) is configured for connection to a mains power supply with a corresponding cable or cord (not shown).

The drive portionof the housingcontains the drive mechanism. As shown in, the drive portiondefines a drive longitudinal axis. The longitudinal grip axisis perpendicular to the drive longitudinal axis.

With reference to, the drive mechanismof the toolincludes a motor, a gearbox, a crank mechanism, and a striking mechanism. The motoris an electric motor that receives electrical energy from the power supply, such as the battery pack, such that the battery packis operably connected to the motor. In embodiments of the toolwithout the battery pack, the motorreceived power from the AC power supply. The motoris provided as a brushless motor or a brushed motor.

The gearbox, in one embodiment, includes reduction gears such that an output of the gearboxrotates more slowly than an output of the motorand with a greater torque. The gearboxis operably connected to the motor. In one embodiment, the gearboxis a relatively heavy element of the drive mechanismand includes a metal housing and metal gears. The longitudinal grip axisextends through the gearbox.

The crank mechanismis operably connected to the output of the gearboxand to an input of the striking mechanism. The crank mechanismis operable to compress a springof the striking mechanismusing rotation of the motorand the gearbox, as powered by the power supply. Moreover, the crank mechanismis configured to release the compressed springso that the springgenerates a striking force. In one embodiment, the crank mechanismis located within the housingat an interface of the grip portionand the drive portion.

The striking mechanismincludes at least the springand an anvil. The striking mechanismis located in the drive portionof the housing. The striking mechanismis operably connected to the gearboxthrough the crank mechanism. In one embodiment, the springis a compression spring. In response to crank mechanismreleasing the compressed spring, the springexerts the striking force on the anvil. The anvilthen strikes a corresponding one of the fasteners, and drives the fastenerinto the workpiece. The fastener magazineis operably connected to the striking mechanismto provide the fastenersto the anvil. The anvilforces the fastenerfrom the fastener magazineat the impact point. Thus, the striking mechanismis configured to strike the corresponding fastenerusing rotation from the gearboxas rotated by the motor, which is supplied with electrical energy from the battery packor other power supply.

As shown in, the toolfurther includes an activation buttonand a safety switch. The activation buttonis mounted on the housing. When the user presses the activation button, assuming the safety switchand all other safety interlocks are active, the drive mechanismis activated for striking the corresponding fastener. As shown in, the finger longitudinal axispasses through the activation button. The exemplary activation buttonis mirrored on opposite sides of the housingto permit left-hand and right-hand grip and activation. In one embodiment, one of the mirrored activation buttonsis depressed to activate the drive mechanismof the tool. In another embodiment, both of the mirrored activation buttonsare pressed simultaneously to activate the drive mechanism, such as by pinching between the user's thumb and forefinger. Thus, the tooluses two points of activation in order to activate the drive mechanism. It is noted that in this embodiment, the safety switchis not included because the pinching action provides two points of actuation.

The safety switch, as shown in, is mounted on the grip portion. The safety switchis activated in order to allow operation of the activation button. Thus, the tool, in one embodiment, provides the two points of activation (i.e., one activation buttonand the safety switch) in order to activate the drive mechanism. In the illustrated embodiment, the safety switchis a lever that is depressed when the user grips the tool. In another embodiment, the safety switchis a passive hand sensor-such as a capacitive zone, inductive zone, or electronic pressure pad-that detects when the grip portionis grasped by the user.

As shown in, the fastener driver toolincludes a shoulder strapthat can be removably fastened with conventional clips(only one of which is visible in) to the housingof the tool. More particularly, the clipsat the ends of the strapengage corresponding a fittingat the end of the drive portionof the housingand another fitting(not visible in) near the end of the power supply portion. Thus, the straphas a first end removably connected to the drive portionof the housingand a second end removably connected to the power supply portionof the housing.

A padis slidably mounted on the strap. The strapcan also be provided with a storage container (not shown) for storing various attachments or components used with the tool.

The shoulder strapallows the user to keep the toolclose at hand during a nailing/stapling process. In many instances, the workpiece must be continuously supported by the user during the process, such as when a molding strip is being fastened to a vertical wall. In instances like these, having the toolclose at hand is essentially so that the user does not need to release the workpiece simply to retrieve the tool. The strapallows the user to carry the toolso that it is always at the ready. In another feature, the strapis arranged and sized to help the user hold the toolwhen aligning and activating the tool. First, the strapis arranged to engage the opposite ends of the fastener driver tool, rather than centered at a single location on the tool. Thus, the strapand the toolessentially form a continuous loop, with the user exerting an outward force from inside the loop as the user maneuvers the tool. Second, the strapis sized so that the strapcan be wrapped around the user's upper body. The combination of these two features allows the user to maintain the strapin tension while maneuvering the toolinto proper alignment with the workpiece. The straptension operates as a lever to support the toolas the toolis moved up and down or side-to-side into proper alignment. This feature not only assists in aligning the tool, it also reduces muscle fatigue in the user. First, the strapbears some part of the weight of the tool. Furthermore, maintaining the strapin tension during use allows the user to activate muscles other than the arm muscles to maneuver the toolso that the workload for supporting and manipulating the toolis shared with the larger muscles of the upper body.

In order to optimally position the center of gravityof the tool, the toolincorporates the majority of the drive mechanisminto the barrel-shaped grip portionof the housing, as shown in, such that the center of gravityis located within the grip portionof the housing. More specifically, in one embodiment, the center of gravityis located at a region of the grip portionengaged by the user's thumb and forefinger. In an embodiment, the center of gravityis located within the gearbox. The center of gravityis a point at which an entire weight of the tool, including the battery pack(when equipped), may be considered as concentrated. The center of gravityis a point at which the tool, including the battery pack(when equipped), is in balance in reference to gravity.

In one embodiment, the optimal center of gravitylocation is achieved by locating the motorand the gearboxcompletely within the grip portionof the housing. This arrangement places a majority of the weight of the drive mechanismin the grip portion, and positions the center of gravityas close to the user's gripping hand as possible in the grip portion. Additionally, a majority of the components of the drive mechanismis disposed within the grip portionso that the weight of those components is directly supported by the user's grip. Moreover, due to the configuration of the housing, the grip portionitself is close as possible to the fastener magazineand the impact point, which significantly reduces or eliminates the counter-clockwise moment generated during positioning and operation of the fastener driver toolversus the prior art fastener driver T discussed above. Specifically, the center of gravity, is oriented at the lower third of the drive portionand is positioned closer to the fastener magazineand the impact pointthan the prior art tool T. Viewed in another way, the grip portionof the toolmoves the user's grip forward toward the drive portionand downward toward the impact point. The housingis thus configured so that the center of gravityis preferably within the envelop of the user's grip on the grip portion, or at least in close proximity to the grip portion. The counter-clockwise moment generated by the prior art tool T (see) is negligible for the toolof the present disclosure. The user can handle the cantilever vertical and horizontal loads (see) with the forearm and the user does not need to resist the moment at the user's wrist. This improves the ability of the user to accurately align the working end of the toolrelative to the workpiece, and reduces the muscular fatigue caused by repeatedly lifting and aligning the tool.

The specific location of the center of gravityis described below in relation to several reference points. For example, in one embodiment, the center of gravityis closer to the activation buttonthan the power supply portionof the housingalong the longitudinal grip axis. Additionally, the center of gravityis closer to the drive portionof the housingthan the power supply portion. Positioning the center of gravityin the illustrated location provides the benefits described above.

In one embodiment, a planenormal to the longitudinal grip axispasses through the center of gravity. Moreover, the planepasses through a thumb and forefinger of an operator of the tool, as the operator grips the grip portionfor activating the activation button. Having the center of gravitynear the operator's thumb and forefinger, along the longitudinal grip axis, provides the benefits described above.

From another perspective, the center of gravityis located between the safety switchand the finger openingalong the drive longitudinal axis, to provide the above-described benefits to the tool.

With reference to, the fastener driver toolof the present disclosure is sized for manual use by any user, ranging from the DIYer to the professional. Exemplary dimensions are shown in, particularly pointing out the location of the center of gravityrelative to the drive portion, the impact point, and the grip portion. Other dimensions are possible in relation to the size and type of fasteners being dispensed at the impact point.

In another embodiment, drive mechanismof the toolincludes the motorand a flywheel apparatus (not shown), as described above in connection with the prior art tool T.

As shown in, another embodiment of the fastener driver tool′ includes a housing′, a battery pack′, a fastener magazine′, a grip portion′, a power supply portion′, a drive portion′, a finger opening′, a longitudinal grip axis′, a finger longitudinal axis′, a drive longitudinal axis′, and a plane′. The tool′ includes a drive mechanism (not shown) that is substantially the same as the drive mechanismof the tool. The tool′ includes an activation button′ through which the plane′ extends. A center of gravity′ of the fastener driver tool′ is optimally located to balance the tool′ and to reduce the undesirable moments and cantilevered loads of the prior art tool T, thereby making the tool′ of the present disclosure more comfortable to operate.

In order to optimally position the center of gravity′ of the tool′, the tool′ incorporates the majority of the drive mechanism into the barrel-shaped grip portion′ of the housing′, such that the center of gravity′ is located within the grip portion′ of the housing′. More specifically, in one embodiment, the center of gravity′ is located at a region of the grip portion′ engaged by the user's thumb and forefinger. The center of gravity′ is aligned along the drive longitudinal axis′ with the activation button′. The plane′ extends through the center of gravity′ and the activation button′. In an embodiment, the center of gravity′ is located within a gearbox (not shown, substantially the same as the gearboxof the tool) of the tool′.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the disclosure are desired to be protected.